The present invention relates to the cooling of molten metal in a mold with a body of a molten metal which is at a lower temperature than the molten metal in the mold.
It has previously been suggested that a casting furnace may employ a body of molten metal as a bath to promote directional solidification of an article in a mold. One apparatus for doing this is disclosed in U.S. Pat. No. 6,308,767. It has also been suggested that a plurality of articles may be floated on a body of molten metal forming a bath so as to form an insulating layer which extends across an upper surface of the bath. One apparatus for doing this is disclosed in U.S. Pat. No. 6,446,700.